Compressor

ABSTRACT

A compressor includes a housing, a suction passage, a compression unit, a drive unit, a suction piping and a thermal insulating member. The housing forms a configuration of the compressor. The suction passage is formed in the housing for introducing a suction gas. The compression unit is provided in the housing for compressing the suction gas. The drive unit is provided in the housing for driving the compression unit. The suction piping is attached to the housing for connecting to the suction passage. The thermal insulating member is interposed between the housing and the suction piping for preventing heat transfer from the housing to the suction piping, and the thermal insulating member has a through hole which interconnects the suction passage and the suction piping.

BACKGROUND OF THE INVENTION

The present invention relates to a compressor, and in, particular to a compressor in which a suction piping for introducing a suction gas is connected to a suction passage formed in a housing.

Japanese Unexamined Patent Publication No. 5-99141 shows this type of compressor.

A compressor shown in FIG. 10 is an enclosed motor compressor. In the compressor, a refrigerant gas in low temperature and low pressure passes a communication tube 113 in a suction muffler 101, a suction chamber 102 and a suction port 103, and is introduced into a cylinder bore 105 by pushing a suction reed 104 away, and is compressed in the cylinder bore 105 to reach high temperature and high pressure. The compressed refrigerant gas passes a discharge port 106, and is discharged to a discharge chamber 107, and passes a discharge line and a discharge tube.

The compressor provides therein a thermal insulating cap 109 made of Polybutyleneterephthalate whose thermal conductivity is small so as to have a space functioning as a thermal insulating layer 108 between the thermal insulating cap 109 and an inner wall of a suction chamber 102. In addition, as shown in FIG. 11, the compressor provides therein a rib 110 on the outer circumferential surface of the thermal insulating cap 109 for forming the thermal insulating layer 108. Further, the compressor provides in a surface of the thermal insulating cap 109 facing to the suction port 103 a small port 111 for blowing back.

Therefore, in the compressor, the thermal insulating cap 109 prevents the refrigerant gas introduced into the suction chamber 102 through the communication tube 113 from being heated. In addition, the space functioning as the thermal insulating layer 108 is filled with the refrigerant gas, thereby preventing heat transfer from a cylinder head 112 to the thermal insulating cap 109.

Thus, heating the refrigerant gas is prevented, and volumetric efficiency of the compressor is improved.

In addition, the compressor is composed such that the refrigerant gas which is blown back is introduced into the thermal insulating layer 108 through the port 111 formed in the thermal insulating cap 109 to damp pulsation caused by the blowing back of the refrigerant gas, thereby reducing vibration and noise of the compressor.

Refer to Japanese Unexamined Patent Publication No. 5-99141, specifically, pages 2-3, and FIGS. 1-2 thereof.

In the above construction where the thermal insulating cap 109 made of Polybutyleneterephthalate, whose thermal conductivity is small so as to have the space functioning as the thermal insulating layer 108 between the thermal insulating cap 109 and the inner wall of the suction chamber 102, is inserted in the compressor, temperature rise of the suction refrigerant gas caused by heat from the cylinder head 112 is prevented. Especially, temperature rise of the suction refrigerant gas caused by heat from the cylinder head 112 on the side of the discharge chamber 107 is prevented. However, the effect is limited to surrounding of the suction chamber 102.

Especially, since the communication tube 113 is heated through the cylinder head 112, the temperature rise of the refrigerant gas in the communication tube 113 is caused before the refrigerant gas is introduced into the suction chamber 102. Thus, the volumetric efficiency of the compressor is not sufficiently improved.

SUMMARY OF THE INVENTION

The present invention is directed to a compressor which reliably prevents temperature rise of a suction gas and improves volumetric efficiency of the compressor.

The present invention provides a following compressor. The compressor includes a housing, a suction passage, a compression unit, a drive unit, a suction piping and a thermal insulating member. The housing forms a configuration of the compressor. The suction passage is formed in the housing for introducing a suction gas. The compression unit is provided in the housing for compressing the suction gas. The drive unit is provided in the housing for driving the compression unit. The suction piping is attached to the housing for connecting to the suction passage. The thermal insulating member is interposed between the housing and the suction piping for preventing heat transfer from the housing to the suction piping, and the thermal insulating member has a through hole which interconnects the suction passage and the suction piping.

Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

The features of the present invention that are believed to be novel are set forth with particularity in the appended claims. The invention, together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments, together with the accompanying drawings, in which:

FIG. 1 is a longitudinal sectional view illustrating a compressor according to a first preferred embodiment of the present invention;

FIG. 2 is a partially enlarged longitudinal sectional view illustrating the compressor according to the first preferred embodiment of the present invention;

FIG. 3 is a cross sectional view illustrating the compressor as seen along the line A-A of FIG. 2;

FIG. 4 is a cross sectional view illustrating the compressor as seen along the line B-B of FIG. 2;

FIG. 5 is a circuit diagram of a refrigerating cycle according to a second preferred embodiment of the present invention and is a longitudinal sectional view illustrating a compressor according to the second preferred embodiment of the present invention;

FIG. 6 is a partially enlarged longitudinal sectional view illustrating the compressor according to the second preferred embodiment of the present invention;

FIG. 7 is a partially enlarged longitudinal sectional view illustrating a compressor according to another example 1 of the present invention;

FIG. 8 is a partially enlarged longitudinal sectional view illustrating a compressor according to another example 2 of the present invention;

FIG. 9 is a partially enlarged longitudinal sectional view illustrating a compressor according to another example 3 of the present invention;

FIG. 10 is a partially enlarged longitudinal sectional view illustrating a prior art compressor; and

FIG. 11 is a cross sectional view illustrating the compressor as seen along the line C-C of FIG. 10:

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A compressor 10 according to a first preferred embodiment of the present invention will now be described with reference to FIGS. 1 to 4.

In the first embodiment, the compressor 10 is a scroll type compressor for a fuel cell and an example thereof is shown in FIG. 1.

The compressor 10 shown in FIG. 1 mainly includes a compression unit, a drive unit and a drive motor unit, and feeds air to an oxygen electrode of the fuel cell.

The compression unit of the compressor 10 includes a fixed scroll member 11, a movable scroll member 12 and a compression chamber 13 which is defined by the fixed scroll member 11 and the movable scroll member 12.

The fixed scroll member 11 includes a fixed scroll base plate 11 a of a disk-shape, a fixed scroll spiral wall 11 b that extends from the fixed scroll base plate 11 a and an outermost wall 11 c. The fixed scroll base plate 11 a and the outermost wall 11 c form a fixed scroll housing 16.

The fixed scroll housing 16 provides a suction passage 14 for introducing air as a suction gas into the compression chamber 13 in a side face thereof, and a discharge passage 15 which is connected to the oxygen electrode of the fuel cell by a discharge piping in the middle of the fixed scroll base plate 11 a.

The movable scroll member 12 includes a disk-shaped movable scroll base plate 12 a, a turbinate movable scroll spiral wall 12 b that extends from the movable scroll base plate 12 a. In the middle of the back surface of the movable scroll member 12 a, a main holding portion 12 c holds a roller bearing 17 and has a cylindrical shape with a bottom. On the outer circumferential side of the main holding portion 12 c, three auxiliary holding portions 12 d each supporting a radial ball bearing 18 and having a cylindrical shape with a bottom are equally arranged, although only one auxiliary holding portion 12 d is shown in FIG. 1.

The drive unit of the compressor 10 includes a drive crank mechanism 19 for generating the circling movement (or the orbital movement) of the movable scroll member 12, a driven crank mechanism 20 for preventing the rotation of the movable scroll member 12, and a crank chamber 21 for accommodating the drive crank mechanism 19 and the driven crank mechanism 20.

The crank chamber 21 communicates with the suction passage 14 and is filled with suction air therein.

The drive crank mechanism 19 includes the main holding portion 12 c, a crankpin 22 a of a drive shaft 22, and the roller bearing 17 which supports the crankpin 22 a.

The driven crank mechanism 20 includes the auxiliary holding portion 12 d, and the radial ball bearing 18 which supports a crankpin 23 a of a driven shaft 23. The rear side of the driven shaft 23 is supported by a double row ball bearing 23 c.

To cancel inertial moment caused upon the orbital movement of the movable scroll member 12, balance weights 22 b, 22 c, 22 d are provided with the drive shaft 22 while a balance weight 23 b is provided with the drive shaft 23, thereby reducing vibration of the movable scroll member 12.

The drive motor unit of the compressor 10 includes a center housing 24, a rear housing 25 which is fixed to the center housing 24 with a bolt (not shown), and a motor chamber 27 which accommodates a drive motor 26 between the center housing 24 and the rear housing 25.

The drive motor 26 which is a synchronous motor includes the drive shaft 22 which extends through the middle of the drive motor 26, a rotor 28 into which the drive shaft 22 is fitted, and a stator 30 which is arranged on the outer circumferential side of the rotor 28 and which a coil 29 is wound around.

Therefore, the drive motor 26 is capable of controlling its rotational speed by an inverter (not shown).

In the drive shaft 22, a front side thereof is supported by a ball bearing 22 e and a rear side thereof is supported by a ball bearing 22 f in the middle of the rear housing 25. In addition, air tight between the drive shaft 22 and the rear housing 25 is kept by a seal 22 g.

In the center housing 24 which covers the drive motor 26, a water jacket 31 is provided so as to adjust the position of the stator 30, and the drive motor 26 is cooled by cooling water.

The drive motor unit is accommodated in the center housing 24 together with the drive unit, and the drive unit and the drive motor unit are partitioned by a support frame 32 which is integrally cast substantially in the middle of the center housing 24.

It is noted that the ball bearing 22 e and the ball bearing 23 c are fitted into the support frame 32.

In addition, the support frame 32 separates the drive unit from the drive motor unit except clearance between the circumferential surface of the drive shaft 22 and the ball bearing 22 e, and clearance between the circumferential surface of the driven shaft 23 and the ball bearing 23 c.

The suction passage 14 of the compressor 10 and a suction piping 33 which is connected to the suction passage 14 will now be described in detail.

The compressor 10 is constructed such that the fixed scroll housing 16, the center housing 24 and the rear housing 25 form a configuration thereof.

The compressor 10 provides therein the suction passage 14 which is formed by the fixed scroll housing 16, as shown in FIG. 2. The suction passage 14 communicates with the compression chamber 13 through an inside of the fixed scroll housing 16, and in addition, communicates with the suction piping 33.

In the present embodiment, on the side of the suction piping 33 of the suction passage 14, a part of the fixed scroll housing 10 extends in a tubular shape, and the tubularly extending portion of the fixed scroll housing 16 is hereinafter referred to a tubular portion 16 a.

On the other hand, the suction piping 33 includes a tubular portion 33 a and a flange 33 b that is formed at the end of the tubular portion 33 a. In FIG. 2, a part of the suction piping 33 which communicates with the suction passage 14 is shown.

It is noted that in the present embodiment the fixed scroll housing 16 which constructs a part of the configuration of the compressor 10 is made of metallic material of aluminum series to achieve weight-saving of the compressor 10.

In the present embodiment, as shown in FIG. 2, a thermal insulating member 34 which is made of thermal insulating material is interposed between the tubular portion 16 a and the suction piping 33.

The thermal insulating member 34 will now be described in detail. The thermal insulating member 34 prevents heat transfer from the tubular portion 16 a to the suction piping 33, and is made of material of resin series whose thermal conductivity is lower than that of metallic material of aluminum series.

As shown in FIG. 3, the thermal insulating member 34 of the present embodiment provides therein a through hole 35 which interconnects the suction passage 14 and the suction piping 33.

In addition, the thermal insulating member 34 provides with a thermal insulating tube 36 inside the suction passage 14. The thermal insulating member 34 and the thermal insulating tube 36 are formed by the same material and, therefore, both of the thermal insulating member 34 and the thermal insulating tube 36 are integrally formed with each other.

One surface of the thermal insulating member 34 of the present embodiment is flattened so as to be capable of closely contacting with the flange 33 b of the suction piping 33, thereby preventing the suction gas from leaking from a space between the suction piping 33 and the thermal insulating member 34.

Meanwhile, the other surface of the thermal insulating member 34 is closely contacted with the distal end of the tubular portion 16 a.

Although means for connecting the suction piping 33, the thermal insulating member 34 and the tubular portion 16 a with each other is not shown in FIG. 2, they may be connected with each other by thread fastening.

In this case, a fastening member such as a screw, a bolt or a nut is used, and it is preferable that thermal conductivity of these fastening members is lower than that of metallic material of aluminum series, which forms the fixed scroll housing 16, to prevent temperature rise of the suction piping 33.

The thermal insulating tube 36 will now be described.

While the suction gas passes through the thermal insulating tube 36 in the suction passage 14, the thermal insulating tube 36 prevents heat transfer from the fixed scroll housing 16 to the suction gas passing through the thermal insulating tube 36, and the thermal insulating tube 36 extends along the suction passage 14 leading to the compression chamber 13.

In the present embodiment, while such explanation is given that the thermal insulating tube 36 is provided in the suction passage 14 formed in the fixed scroll housing 16, as shown in FIG. 4, a space 37 functioning as a thermal insulating layer is formed by an inside surface 14 a of the suction passage 14 and an outside surface 36 a of the thermal insulating tube 36.

Thus, the thermal insulation effect by the thermal insulating tube 36 and the thermal insulation effect by the space 37 as the thermal insulating layer are simultaneously achieved, and it is intended to further prevent heating from the fixed scroll housing 16 to the suction gas passing through the thermal insulating tube 36.

Further, in the present embodiment, the diameter of the through hole 35 of the thermal insulating member 34 coincides with the inside diameter of the suction piping 33 and the inside diameter of the thermal insulating tube 36, thereby stabilizing flow of the suction gas passing the suction piping 33 and the thermal insulating tube 36.

The operation of the compressor 10 of the present embodiment will now be described.

As the compression unit is driven by drive of the drive unit of the compressor 10, the suction gas is introduced into the compression chamber 13 through the suction piping 33 and the suction passage 14.

The suction gas in the compression chamber 13 is compressed by the compression unit which is continuously driven, and the compressed suction gas is discharged to a discharge piping through the discharge passage 15.

When the suction gas is compressed by the compression unit, the compressed suction gas rises in temperature and pressure, so the fixed scroll housing 16 is heated through various portions of the compressor 10 to rise the temperature of the fixed scroll housing 16.

The compressor 10 according to the present embodiment produces the following beneficial effects.

(1) Since the thermal insulating member 34 is interposed between the tubular portion 16 a and the suction piping 33, the thermal insulating member 34 prevents heat transfer from the fixed scroll housing 10 to the suction piping 33. Thus, in the suction piping 33, the temperature rise of the suction gas is prevented.

(2) Since the thermal insulating tube 36 which is integrally formed with the thermal insulating member 34 is provided in the suction passage 14, the thermal insulating tube 36 prevents heat transfer from the fixed scroll housing 16 to the suction gas in the suction passage 14, thereby preventing the temperature rise of the suction gas passing the thermal insulating tube 36 in the suction passage 14. Therefore, the temperature rise of the introduced suction gas in a range from the suction piping 33 to the compression chamber 13 through the suction passage 14 is reliably prevented.

(3) Since the space 37 as a thermal insulating layer is interposed between the inside surface 14 a of the suction passage 14 and the outside surface 36 a of the thermal insulating tube 36, the space 37 provides the suction gas with the thermal insulation effect. Therefore, in the suction piping 33 and the suction passage 14, the temperature rise of the suction gas passing the thermal insulating tube 36 is further prevented.

(4) Since the thermal insulating member 34 and the thermal insulating tube 36 prevent the temperature rise of the suction gas which has not been compressed, volumetric efficiency of the compressor 10 is not reduced, and in addition, the volumetric efficiency of the compressor 10 is easily maintained in a stable state.

(5) Since the thermal insulating member 34 and the thermal insulating tube 36 are integrally formed with each other, increase of the number of parts of the compressor 10 is prevented, thereby contributing to reduction of working time for assembly.

(6) Since the thermal insulating member 34 and the thermal insulating tube 36 are made of material of resin series and are integrally formed with each other, even if the fixed scroll housing 16 made of metallic material of aluminum series whose thermal conductivity is relatively high reaches high temperature, in the suction piping 33 and the thermal insulating tube 36 the temperature rise of the suction gas due to heat transfer from the fixed scroll housing 16 is reliably prevented.

(7) Since the suction piping 33, the through hole 35 of the thermal insulating member 34 and the thermal insulating tube 36 have the same diameter, the flow of the suction gas from the suction piping 33 to the thermal insulating tube 36 is stabilized, thereby contributing to the prevention of the variation of temperature distribution of the suction gas, and volumetric efficiency of the compressor 10 is further easily maintained in a stable state.

A compressor 40 according to a second preferred embodiment of the present invention will now be described.

In the present embodiment, the compressor 40 which is applied to a refrigerating cycle is shown in FIG. 5.

The refrigerating cycle of FIG. 5 includes the compressor 40, a condenser 41, an expansion valve 42 and an evaporator 43.

The compressor 10 of the present embodiment is connected to the condenser 41 by a discharge piping 44 while being connected to the evaporator 43 by a suction piping 45.

The condenser 41 and the evaporator 43 are connected with each other by a piping 46 and a piping 47 through the expansion valve 42.

Therefore, in this refrigerating cycle, a refrigerant gas as a suction gas, which is discharged from the compressor 40, is sent through the discharge piping 44, the condenser 41, the piping 46, the expansion valve 42, the piping 47, the evaporator 43 and the suction piping 45 and is then introduced into the compressor 40 again.

In the compressor 40, as shown in FIG. 5, a front housing 50 is joined to the front end surface of a cylinder block 48 through a gasket 49, and a crank chamber 51 as a control chamber is defined therein.

Also, a rear housing 53 is joined to the rear end surface of the cylinder block 48 through a valve plate 52, and in the rear housing 53 a discharge chamber 54, a discharge passage 55 and a suction passage 56 are defined.

The discharge passage 55 is connected to the discharge piping 44, and the suction passage 56 is connected to the suction piping 45.

The cylinder block 40 and the front housing 50 form shaft holes in the center thereof, respectively. A drive shaft 57 extends through the shaft holes and are rotatably supported by radial bearings 58 a, 58 b.

On the front side of the drive shaft 57, a shaft seal device 59 is arranged

In the crank chamber 51, a lug plate 61 as a rotary support member for a swash plate 60 as a cam plate is fixed to the drive shaft 57 so as to be integrally rotated with the drive shaft 57.

The swash plate 60 is arranged in the crank chamber 51 in such a state that the drive shaft 57 extends through a through hole 62 formed in the swash plate 60.

The lug plate 61 and the swash plate 60 interpose a hinge mechanism 63 therebetween.

The swash plate 60 is synchronously rotated with the lug plate 61 and the drive shaft 57 by the connection with the lug plate 61 through the hinge mechanism 63 and the support of the drive shaft 57, while being slidable along a direction of an axis of the drive shaft 57 and inclinable relative to the axis of the drive shaft 57.

A plurality of cylinder bores 64 is formed in the cylinder block 48, and a piston 65 is accommodated in each cylinder bore 64 for reciprocation.

Each piston 65 and the valve plate 52 define a compression chamber 66 which varies its volume in accordance with the reciprocation of the piston 65.

Each piston 65 is engaged with the periphery of the swash plate 60 through a pair of shoes 67.

Therefore, the rotational movement of the swash plate 60 accompanied by the rotation of the drive shaft 57 through the lug plate 61 and the hinge mechanism 63 is converted into the reciprocation of the pistons 65 through the shoes 67.

The swash plate 60, the lug plate 61, the hinge mechanism 63 and the shoes 67 constructs the drive unit which converts the rotational movement of the drive shaft 57 into the compression movement for compressing the refrigerant gas in the compression chamber 66.

The compression chamber 66 is connected to the discharge chamber 54 through a discharge port 68.

The valve plate 52 and the rear housing 53 interpose therebetween a discharge valve forming plate 69 which integrally forms discharge valves and a retainer forming plate 71 which integrally forms retainers 70.

It is noted that the retainer forming plate 71 is also used as a gasket, and the cylinder block 48 and the valve plate 52 interpose a gasket 72 therebetween.

In accordance with the rotation of the drive shaft 57, the refrigerant gas is introduced into a suction chamber 73 through the suction passage 56, and the introduced refrigerant gas is compressed in the compression chamber 66, and is discharged outside the compressor 40 through the discharge part 68, the discharge chamber 54 and the discharge passage 55.

As the drive shaft 57 of the compressor 40 is rotated by power of an engine, the swash plate 60 is rotated through the lug plate 61 and the hinge mechanism 63.

Therefore, each piston 65 is reciprocated in the corresponding cylinder bore 64 through tho corresponding shoes 67, the suction gas is introduced from the suction piping 45 to compression chamber 66 through the suction passage 56 and the suction chamber 73.

Further, the piston 65 is shifted to the compression process, the refrigerant gas in the compression chamber 66 is discharged to the discharge chamber 54 pushing a discharge valve away from the discharge port 68.

In the compressor 40, the suction passage 56 and the suction piping 45 which is connected to the suction passage 56 will now be described.

As shown in FIG. 6, a configuration of the compressor 40 mainly includes the front housing 50 and the rear housing 53. In the present embodiment, the rear housing 53 forms therethrough the suction passage 56.

The suction passage 56 is connected to the suction chamber 73 formed by the rear housing 53, and the suction chamber 73 is connected to the compression chamber 66.

The rear housing 53 of the present embodiment is made of metallic material of aluminum series similarly to the aforementioned embodiment.

Although the suction piping 45 is connected to the suction passage 66, the rear housing 53 and the suction piping 45 interpose a thermal insulating member 74 therebetween.

The suction piping 45 includes a tubular portion 45 a and a flange 45 b that is formed on one end of the tubular portion 45 a. In FIG. 6, a part of the suction piping 45 which is connected to the suction passage 56 is shown.

On the other hand, the thermal insulating member 74 is made of material of resin series whose thermal conductivity is lower than that of metallic material of aluminum series.

The thermal insulating member 74 provides therein a through hole 75 which interconnects the suction passage 50 and the suction piping 45 similarly to the aforementioned embodiment, and in addition, provides with a thermal insulating tube 76 arranged inside the suction passage 56, and the thermal insulating member 74 and the thermal insulating tube 76 are integrally formed with each other.

One surface of the thermal insulating member 74 of the present embodiment is flattened so as to be capable of closely contacting with the flange 45 b of the suction piping 45, and the other surface of the thermal insulating member 74 is closely contacted with the surface of the rear housing 53.

Meanwhile, the thermal insulating tube 76 extends along the suction passage 56 leading to the suction chamber 73.

It is noted that although in the present embodiment the thermal insulating tube 76 is provided in the suction passage 56 formed in the rear housing 53, the inside diameter of the suction passage 56 is set at a smaller value than that of the aforementioned embodiment such that an inside surface 56 a of the suction passage 56 contacts with an outside surface 76 a of the thermal insulating tube 76.

Further, in the present embodiment, the diameter of the through hole 75 of the thermal insulating member 74 coincides with the inside diameter of the suction piping 45 and the inside diameter of the thermal insulating tube 76.

The compressor 40 according to the present embodiment performs the beneficial effects basically similar to the effects (1)-(7) which are achieved by the compressor 10 of the first embodiment, except the effect (3).

Further, even when the inside diameter of the suction passage 56 is not capable of setting at a large value, the thermal insulating tube 76 is capable of being provided in the suction passage 56 by contacting the thermal insulating tube 76 provided in the suction passage 56 with the inside surface 56 a of the suction passage 56, thereby preventing the temperature rise of the refrigerant gas as the suction gas, and in addition, ensuring a needed flow rate of the refrigerant gas.

The compressors according to some other examples of the first and second embodiments will now be described with reference to FIGS. 7 to 9.

Therefore, in the present examples, for convenience of explanation, a part of the signs used in the previously explained first and second embodiments is commonly used, and explanation of the configuration common to those of the first embodiment and second embodiments is omitted and incorporated herein.

In another example 1, a compressor 80 is another example of the compressor 10 of the first embodiment and, as shown in FIG. 7, is such a compressor that the suction piping 33 and the tubular portion 16 a interpose a thermal insulating member 81 therebetween.

The thermal insulating member 81 provides therein a through hole 82 whose diameter is the same as the inside diameter of the suction piping 33.

The compressor 80 of the example 1 does not provide with the thermal insulating tube 36 described in the first embodiment, and the inside diameter of the suction passage 14 is set at a larger value than that of the suction piping 33.

The compressor 80 of the example 1 is at least capable of preventing heat transfer from the tubular portion 16 a to the suction piping 33, and therefore does not cause the temperature rise of the suction piping 33, thereby being capable of preventing the temperature rise of the suction gas in the suction piping 33.

In another example 2, a compressor 85 is another example of the compressor 10 of the first embodiment and, as shown in FIG. 8, is such a compressor that a suction piping 80 and a thermal insulating member 87 are combined with each other by thread fastening.

The suction piping 86 provides a threaded portion 86 a on the outside circumferential surface of the end thereof, and the thermal insulating member 87 provides inside thereof a threaded portion 87 a corresponding to the threaded portion 86 a.

In the example 2, the thermal insulating member 87 provides with the thermal insulating tube 36, and in addition, the inside surface 14 a of the suction passage 14 and the outside surface 36 a of the thermal insulating tube 36 form the space 37 therebetween. Further, the inside diameters of the suction piping 86, a through hole 88 of the thermal insulating member 87 and the thermal insulating tube 36 coincide with each other.

In the compressor 85 of the example 2, the suction piping 86 and the thermal insulating member 87 are capable of pre-combining with each other, and therefore the suction piping 86 is connected to the suction passage 14 by connecting the thermal insulating member 87 to tubular portion 16 a, thereby contributing to reduction of working time for assembly.

In another example 3, a compressor 90 is another example of the compressor 40 of the second embodiment and, as shown in FIG. 9, is such a compressor that a first thermal insulating member 91 and a second thermal insulating member 92 which are made of different material from each other are combined with each other, and these thermal insulating members 91, 92 are interposed between the suction piping 45 and the rear housing 53 near the suction passage 56.

In the example 3, the first thermal insulating member 91 on the side of the rear housing 53 is made of material whose thermal conductivity is lower than that of the rear housing 53. For example, the first thermal insulating member 91 is made of metallic material of iron series. The second thermal insulating member 92 on the side of the suction piping 45 is made of material whose thermal conductivity is lower than that of the first thermal insulating member 91. For example, the second thermal insulating member 92 is made of material of resin series.

In the example 3, in addition, the first thermal insulating member 91 provides with the thermal insulating tube 76, and the inside diameters of the suction piping 45, through holes 93, 94 of the thermal insulating members 91, 92 and the thermal insulating tube 76 coincide with each other.

In the compressor 90 of the example 3, since the first thermal insulating member 91 and the second thermal insulating member 92 which are made of different material from each other are combined with each other, heat transfer from the housing 53 to the suction piping 45 is reliably prevented and there is no fear of causing the temperature rise of the suction piping 45. Thus, the temperature rise of the refrigerant gas as a suction gas in the suction piping 45 is further prevented.

The first thermal insulating member 91 and the second thermal insulating member 92 are not only used in combination, but also either of the first thermal insulating member 91 and the second thermal insulating member 92 is capable of being used in accordance with use of the compressor 90 and status of use thereof.

It should be understood that the invention is in no way limited to the first and second embodiments, and the aforementioned examples 1-3, but may be changed in various ways without departing from the spirit and scope of the invention and for example, the following modifications may be made.

In the aforementioned first and second embodiments, and the examples 1-3, although the scroll type compressor or the piston type compressor of swash plate type is employed as a compressor, the compressor at least provides with a suction passage which is connected to a compression chamber and a suction piping which is connected to the suction passage. For example, the present invention is capable of being applied to a vane compressor or a rotary compressor. That is, kinds and forms of the compressor are not inquired.

In the aforementioned first and second embodiments, and the examples 1-3, although the thickness of the thermal insulating member is shown in a similar size to the thickness of the suction piping, the thickness of the thermal insulating member is not limited to the above thickness. As the thickness of the thermal insulating member is increased, heat transfer from the thermal insulating member to the suction piping is effectively prevented. When the thickness of the thermal insulating member is increased to a relatively large size, the thermal insulating member may be connected to the suction piping and the housing separately.

In the aforementioned first and second embodiments, and the examples 1-3, the diameter of the through hole provided with the thermal insulating member coincides with the inside diameter of the suction piping, but the diameter of the through hole only needs the diameter which is the same as or larger than the diameter of the suction piping. In this case, in the suction piping, obstacle upon passage of the suction gas does not occur.

In the aforementioned first and second embodiments, and the examples 2, 3, although the thermal insulating member and the thermal insulating tube are integrally formed with each other, the thermal insulating member and the thermal insulating tube may be formed separately.

In the aforementioned first and second embodiments, although the suction piping, the thermal insulating member and the housing near the suction passage are screwed to each other by the fastening member such as a bolt, they may be joined to each other by welding or adhering in accordance with the material of the suction piping, the thermal insulating member and the housing without limitation of screwing. Also, in the example 2, the way of the combination of the thermal insulating member and the suction piping is not limited to thread fastening, and is freely achieved by means such as adhesion.

Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive and the invention is not to be limited to the details given herein but may be modified. 

1. A compressor comprising: a housing for forming a configuration of the compressor; a suction passage formed in the housing for introducing a suction gas; a compression unit provided in the housing for compressing the suction gas; a drive unit provided in the housing for driving the compression unit; a suction piping attached to the housing for connecting to the suction passage; and a thermal insulating member interposed between the housing and the suction piping for preventing heat transfer from the housing to the suction piping, the thermal insulating member having a through hole which interconnects the suction passage and the suction piping.
 2. The compressor according to claim 1, wherein thermal conductivity of the thermal insulating member is lower than that of the housing.
 3. The compressor according to claim 1, wherein the housing is made of metallic material of aluminum series, the thermal insulating member being made of one of material of resin series and metallic material of iron series.
 4. The compressor according to claim 1, wherein the thermal insulating member and the suction piping are combined with each other.
 5. The compressor according to claim 1, further comprising a thermal insulating tube provided In the suction passage, the thermal insulating member and the thermal insulating tube being integrally formed with each other.
 6. The compressor according to claim 5, wherein the suction passage and the thermal insulating tube form a space therebetween.
 7. The compressor according to claim 5, wherein a diameter of the through hole of the thermal insulating member coincides with an inside diameter of the suction piping and an inside diameter of the thermal insulating tube. 